4 Answers

Mass is a reflection of how much matter makes up an object, that is all the atoms and molecules that make an object what it is. Mass of an object will not change based upon location. If you have a box of 50 [kg], then it contains enough matter (atoms and molecules) to give it that much mass. If you snap your fingers and the box is now on the moon, it's mass will not...

Mass is a reflection of how much matter makes up an object, that is all the atoms and molecules that make an object what it is. Mass of an object will not change based upon location. If you have a box of 50 [kg], then it contains enough matter (atoms and molecules) to give it that much mass. If you snap your fingers and the box is now on the moon, it's mass will not be any different. All the matter (atoms and molecules) that make it up will still be present.

Weight, however, will be different. It is a measurement of the force due to gravity acting on an object. Every object with mass exerts a gravitational pull on every other object with mass. I'm exerting a gravitational pull on you as you read this answer. So is the Earth. If you were to jump in the air, where would you be pulled to though? Obviously, you'd be pulled back down to the ground and not towards me. Why? Because gravity depends upon two factors, size and distance. The Earth is much more massive than myself and exerts a greater pull than I ever could. Then you may argue that Jupiter or the sun is more massive than the Earth, why aren't you pulled there? Because both Jupiter and the sun are too far away for their gravitational pull to be of any influence. In short the farther you are from an object (or higher up in the case of say mountains vs. sea level), the less pull you feel and the less you weigh.

So, for your question, mass will not be any different. The weight will be though. The moon is less massive than earth and exerts roughly 1/6 the gravitational attraction. As a result, that box will weigh 1/6 the amount it does on Earth. Of the possible answers, C is the correct choice.

This is because mass a quantity that stays constant no matter where we are in the universe. The mass of an object is never affected by other factors such as gravity.

So, option A. Greater mass, is incorrect.

Weight, however, is the quantity that is affected by gravity and would vary based on your position, i.e. if you are on earth or the moon in this case.

The weight of an object on the moon is 1/6th of that of its weight on earth, since the mass of the moon is a lot less than that of earth. So, the weight of an object of mass 50 kg would be 500 N (taking g = 10 m/s) and on the moon would be 83.3 N (500`-:` 6). So, the weight would always be less on the moon.

So, options B and D cannot be true as well.

The answer is in fact C, because the mass of any object is a constant (scalar) quantity.

User Comments

Mass of a body is a measure of matter it contains and is independent of gravity and hence the object will have the same mass on Earth as well as on the Moon.

Weight,however, is a function of gravity and is the product of mass and acceleration due to gravity. Moon has about 1/6th the gravity of earth and hence the weight of the object would be 1/6 of its weight on Earth.

In my opinion the answer is C. Inertial mass is intrinsic, gravitational mass can be shown to be manifestly the same as inertial mass. These are the two most common meanings when someone uses the term mass. The mass does not change because the mass (as it commonly defined) is an intrinsic property of the object in question.